Speech recognition converts spoken words into text. In an example, a user speaks a voice command into a microphone of a device (e.g., a mobile device). The device captures the voice command as an audio signal and transmits the audio signal to a speech recognition system. The speech recognition system converts the audio signal into a digital waveform using a Pulse Code Modulation technique. The speech recognition system converts the digital waveform into a set of discrete frequency bands using a Fast Fourier Transform technique.
The speech recognition system is configured to recognize the discrete frequency bands. In an example, the speech recognition system includes a database for storing data indicative of phonemes. In an example, a phoneme is a unit of speech in a language. The speech recognition system matches the discrete frequency bands to the phonemes in the database to covert the discrete frequency bands into text.